My doctor told me to stay away from soy. In addition, my girlfriend ( we are both over 40 FYI) can drink a high soy drink like milk or creamer and it gives her "hot flashes" within 15 minutes. So I would say based on that it has a real hormonal affect.

Why do you need it? I'm lactose intollerant too and I just use water. Cheaper, tastes better (IMO), and doesn't affect to estrogen. I've also used fruit juice in the past, but water works best. The shake is for protein, it doesn't have to be gourmet.

Why do you need it? I'm lactose intollerant too and I just use water. Cheaper, tastes better (IMO), and doesn't affect to estrogen. I've also used fruit juice in the past, but water works best. The shake is for protein, it doesn't have to be gourmet.

I've been using water in my shakes for the past 6 years or so for 99% of the time. Coffee, Gatorade, milk, and eggnog have been good though. F soy; I hate how its in so many food products now. Metrx bars are sh*tty as they are contaminated with soy.

I would imagine that soy protein ISOLATE should have no significant negative effects associated with soy intake. Reason being, if it's a protein isolate, it shouldn't have any of the phytoestrogens in soy. So it probably isn't a big deal as long as it's an isolate. Otherwise at worst its amino acid profile isn't as good. For vegetarian proteins, I believe gemma pea is very good.